Since we all have to wait awhile for home automation to be the norm, we would have to do with reminder pads and boards for a longer while.
A pad, however, is easier to misplace. If you have kids, they are also more likely to play with it, hide it, or pile their toys on top of it. This is where reminder boards have an advantage. Attached safely on a high-traffic wall or surface (like your fridge door), with a pen attached to it with a string, you can now easily jot things that need to be bought and done. Chores can easily be ticked off and the family schedule easily monitored.
You can also opt to use a whiteboard or a glass surface set in frames, and then just use whiteboard markers. If you have older kids, you can also freely use colored ones without fear of having an incomplete set for all your categories.